UNUSUAL TEMPERATURE DEPENDENCE OF COERCIVITY IN Ε-FE2O3 PHASE

1 Nikolić Violeta N.
Co-authors:
1 Tadić Marin 1 Mraković Ana 1 Spasojević Vojislav
Institution:
1 University of Belgrade - Vinča Institute of Nuclear Sciences, Condensed Matter Physics Laboratory, P.O. Box 522, 11001 Belgrade, Republic of Serbia, violeticanik@gmail.com
Conference:
9th International Conference on Nanomaterials - Research & Application, Hotel Voronez I, Brno, Czech Republic, EU, October 18th - 20th 2017
Proceedings:
Proceedings 9th International Conference on Nanomaterials - Research & Application
Pages:
27-32
ISBN:
978-80-87294-81-9
ISSN:
2694-930X
Published:
8th March 2018
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
678 views / 337 downloads
Abstract

Nano iron oxides have been intensively investigated due to their various potential biomedical applications. ε-Fe2O3phase exerted internal coercivity value up to ~20 kOe, high Curie temperature (Tc= 510 K), and magnetoelectric character. Accordingly, epsilon phase is recognized as a suitable material for medical spintronic biosensors production, that present important part for the lab-on-a-chip systems. Noteworthy, ε-Fe2O3 phase exerts peculiar magnetic behavior. To get better insight into the magnetism of this material, ε-Fe2O3/SiO2 sample was prepared by the combination of the sol-gel synthesis and microemulsion method (Tann=1050 °C, tann= 4h). Afterwards, the sample was exposed to post-annealing treatment at 100 °C and 200 °C. Synthesized material was preliminary examined by XRD and SQUID techniques. Coercivity changes, induced by the post-annealing temperature oscillations, were monitored by hysteretic measurements. Sample annealed at 1050 °C for 4h, showed coercivity ~20 kOe. The same sample performed to the post-annealing treatment at 100 °C, exerted significantly decreased coercivity (~1600 Oe). Further rise of the post-annealing temperature (200 °C) resulted in the increased coercivity ~15 kOe. Obtained study showed that there is insufficientknowledge concerning theε-Fe2O3coercivity changes of thepolymorph. The more detailed investigation will be conducted, in order to advance the control of the epsilon phase magnetic properties.

Keywords: ε-Fe2O3 phase, coercivity, phase transformations

© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Scroll to Top